1. Field of the Invention
The invention relates to a device for the finishing treatment of shaft workpieces. The device comprises a carrier, at least one jaw for exerting contact pressure on the workpiece, and a linear guide for the jaw.
2. The Prior Art
Finishing treatment devices are known from German Patent No. A 196 07 776. In this case, the device comprises two jaws exerting contact pressure, arranged on arms of linear guides. The arms, in turn, are guided on a portal-like transverse carrier, and are connected with each other by an electro-mechanical or hydraulic chucking device. The contact pressure for the finishing treatment is generated by the chucking device. The device is equipped with four guides which has high construction costs. Since the arms are long and are guided on a transverse carrier, the device has relatively low rigidity. This rigidity varies depending on the position the jaws are located on the arms. Finishing defects may occur in the finishing treatment as a result of such inadequate stiffness. Furthermore, when a workpiece is loaded and unloaded, problems may occur because the jaws may be displaced against each other in the longitudinal direction of the arms. Costly and precise operating positioning devices are needed so that the jaws will maintain defined positions during a workpiece change.
The invention provides a compact and structurally simple device having only a few moving components for the finishing treatment of shafts. This device provides high and invariable rigidity by virtue of its construction.
The present invention accomplishes these and other objects by providing a transverse guide consisting of a main carriage guided on a carrier. The main carriage is radially aligned with respect to the axis of rotation of the workpiece and the main carriage contains a fork-shaped head located on the side facing the workpiece. A guide rail is disposed on a linear guide of the jaw, and is inserted between the legs of the fork-shaped head at a right angle relative to the direction of movement of the transverse guide. In the course of treatment of the workpieces, the guide of the main carriage is free of bending moments, so as to assure a smooth and precise guidance of the transverse guide. The two jaws are movably guided on the guide rail, whereby the working surfaces of the jaws extend around the workpiece. The working surfaces can be fitted with hones or designed for operating with a finishing belt. To generate the contact pressure required for the finishing treatment, the jaws can be connected to each other by an electromechanical, hydraulic or pneumatic chucking device. The adjustment range of the chucking device is designed so that the jaws can opened for loading and unloading a workpiece.
The jaws are in the form of cantilevered structural components and contain a carriage at their rearward ends. The carriage is guided on the guide rail. The working surface is located at the projecting ends of the jaws, and extends around the workpiece in a curved manner.
When the main portion and the lifting bearings of a crankshaft or a camshaft are worked for finishing purposes, a multitude of the devices can be arranged next to one another in the longitudinal direction of the workpiece. After the finishing treatment of the workpiece is completed, the jaws are opened and the workpiece is removed. The insertion of a new workpiece is substantially simplified if the main carriages of the devices maintain their positions. According to a preferred embodiment of the invention, the main carriage has a rearward end that projects beyond the carrier. This end can be locked when the workpiece is not being operated. A positioning device, as well as a chucking device, are preferably associated with the rearward end, which has a profile section cooperating with the positioning device. When the positioning device is actuated, the main carriage is in a position that is preset by the profile section of the rearward end. Furthermore, by actuating the chucking device, the rearward end can be fixed in any desired position.